1. Field of the Invention
The present invention relates to a transformer, and particularly to a transformer used in a communication connector for stably transmitting signals.
2. Related Art
Signal transmission, especially high-speed signal transmission, is subject to current and external interference. Currently, in order to make signal transmission stable, transformers are popularly used in communication connectors for signal transmission between computers and peripherals. Such a transformer often has filtering function, as disclosed in U.S. Pat. Nos. 4,754,370, 5,015,204, 5,139,442, 5,687,233, 5,872,492, 5,833,496, 6,102,741 and 6,456,180.
The conventional transformer usually has inductive/impedance coils. Each inductive/impedance coil has two ends respectively serving for mating with a mating connector and soldering to a PCB, sometimes serving for connecting with the communication connector and soldering to a PCB. There are some deficiencies of this design in manufacture and use as followings.
(1) manufacture process is inflexible. An end of the inductive/impedance coil, which serves for mating with a mating connector or serves for connecting with the communication connector, has to be assembled on an assembling board, or has to connect with terminals of the communication connector via a series of connecting process in advance. Then it connects with a PCB before testing signal transmission of each terminal. Thus the manufacture process is constrained of series connecting/assembling first. Some conventional communication connectors provide instruction lights for displaying proper signal transmission. Similarly, the instruction lights have to be mounted on a housing and assembled to a PCB first before testing.
(2) mass production is inefficient. Manufacturing as described above, once problems are found in testing process, for example, a terminal fails to communicate with inductive/impedance coils or instruction lights can't work, the defective products have to back to the series connected/assembled mentioned before to reproduce. This makes manufacture process troublesome.